Exponential horn printer



Get. 12, 19% M. NAlMAN 3,211,088

EXP ONENT IAL HORN PR I NTER Filed May 4, 1962 TR ANSDUCE =2 VOLTAGE SOURCE INVENTOR MARK NAIMAN BY AJMLIZQLN ATTORNEY United States Patent 3,211,088 EXPONENTIAL HORN PRINTER Mark Naiman, Philadelphia, Pa., assignor to Sperry Rand Corporation, New York, N.Y., a corporation of Delaware Filed May 4, 196 2;, Ser. No. 192,515 2 Claims. (Cl. 101114) This invention relates to printing devices and more particularly to that type of printing device wherein there is no direct contact between a moving print means and the surface upon which the printing is placed.

Despite the advances in computer technology, such as making the arithmetic and other internal organs of the computer faster in operation, the computing systems as a whole have not increased greatly in speed of operation. This lack of overall speed increase is due to a large measure to the relatively low speeds of operation possible with conventional and so-called high-speed types of printing means used to provide a printed record of the computer output information. These printing devices, when compared to the speed of operation of the computer elements themselves, require relatively long periods of time for selection of the character to be printed, movement of the character to contact a surface or the surface to contact the character and return to the normal intermediary condition. For example, if the printing device were a band printer, time would be required to move the band to a position wherein the character was in proper alignment for printing. Then more time would be consumed in moving the band to contact the paper or move the paper to contact the band and then allow the moving member to return to its normal intermediary condition, ready for the next print operation. In those types of systems in which the printing member is in constant motion, a period of time is required to allow the print member to move in its cycle sufiiciently to permit the desired character to be presented to the surface to be printed upon. The time required for movement to permit contact and the return to a normal condition will be similar to that of the band printer described above. Further, due to the fact that the paper is permit-ted to move, during the print operation, usually in a direction transverse to the direction of movement of the print mechanism, special positioning techniques are required to prevent the individual characters from walking up or down the surface as a row across the width of the surface is printed.

Also, due to the use of light weight bands to support or carry the desired printing characters, care must be taken to provide proper back-up for the bands regardless of whether they are moved or merely struck by a moving paper depending upon the type of band printer employed.

Thus it is obvious that if it were possible to reduce the time require-d to position a character or allow it to rotate until the proper character was presented as well as the time required to move the character or paper the overall speed of operation of the print apparatus and in turn, that of the computational system would be greatly increased.

As briefly stated, this invention makes possible a system of printing whereby many of the steps required in printing by known conventional printing devices are eliminated thereby increasing the overall speed of operation. These steps are:

(1) Positioning of the print member-whether by direct movement or by allowing it to rotate until the correct character position is reached.

(2) Contact between character and paper-whether the print member is moved to contact the surface or the surface is moved to contact the print member, and

3,211,088 Patented Oct. 12, 1965 (3) Reset or return of the print member to its neutral or normal position.

The invention employs a matrix composed of a number of individual print means each of which may print an individual dot. By proper selection of the location and number of these dots, there will be printed a particular character or letter in discontinuous form upon the printing surface. The density of the dots making up the letter or character may be as great as desired simply by arranging "for a larger or smaller matrix. Each of the individual print means, which produces a single dot, is made in the form of a horn open at the small end. This horn conducts a pressure wave produced at the larger end, to the small end, carrying with it ink contained within the horn. To print a dot, a transducer, placed at the larger end, is excited to produce a pressure wave which travels up the horn. This pressure wave forces the ink from the smaller end to the under surface of the paper, (such paper being moved adjacent to said smaller end) thereby producing the desired spot. Each of these transducers may in turn be connected to a selection matrix which can be operated in accordance with the pattern or character desired to print.

Thus there is no direct contact between a moving print member and the surface to be printed upon as in conventional print devices, there is only the indirect type of contact which results from a contact of the printing ink with the surface to be printed upon.

It is therefore an object of this invention to provide a novel form of print means wherein no direct contact is made between a moving printing device and the surface upon which the printing is to be placed.

-It is another object of this invention to provide a novel printing device not employing preformed characters but rather employing a device wherein a particular form of the character or symbol may be selected at will.

It is another object of this invention to provide a novel printing device the individual unit of which consists of an exponential horn with a crystal capable of forming shock waves mounted within its large opening.

It is a further object of this invention to provide a shock operated printing system.

It is yet another object to provide a printing system with an increased speed of operation.

Other objects and features of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention, and the best modes which have been contemplated for carrying it out.

In the drawings:

FIGURE 1 illustrates a device constructed in accordance with the basic concept of the invention;

FIGURE 2 shows an arrangement for placing the devices constructed in accordance with FIGURE 1 in a matrix for printing composite letters or symbols;

FIGURE 3 shows an alternative arrangement for placing the individual print means in a matrix to produce composite letters or characters;

FIGURE 4 shows the manner in which the tape will appear after it has been printed with a device constructed in accordance with this invention.

Similar elements will receive similar reference characters in all of the respective figures.

Referring to FIGURE 1 there is shown an individual print element constructed in accordance with this invention. The device consists of an aperture 104 bored into the mounting surface 102. The aperture 104 is in the form of an exponential horn with the small end 166 placed in a position closest to the surface upon which it is desired to print; that is the surface 198 of a continuous tape or paper 110. It should be understood that the principles of the invention are not limited to exponential horns, but are equally applicable to other horn configurations. The use of the exponential horn is merely illustrative of a preferred embodiment and no limitation of the application of the inventive concepts is intended thereby. The paper or tape 110 is moved in a direction to the right as shown by the arrow head by means not shown. The larger end 112 of the exponential horn is placed in close proximity to a pressure producing transducing device 114. The transducing device is connected by a set of leads 116 and 118 to a source of voltage 120. The

'trahsducing device 114 may conveniently take the form of a piezoelectric crystal or a magnetostrictive element, or any other type of element which upon electrical or mechanical actuation produces large amplitude pressure waves. In the present preferred embodiment, the pressure producing transducer is a piezoelectric device. The

entire lower portion of the exponential horn as well as the transducer are placed in a pool or supply of liquid ink 122. In other words, the ink entirely covers the transducer and extends within the exponential horn to a given level. If it is desired to have this particular print element produce a spot of ink upon the surface 108 of the tape 110, switch 117 is closed applying a voltage from source 120 to the piezoelectric transducer 114 by the lines 116 and 118. The application of this electric force to the transducer causes it to expand. This mechanical motion is transmitted to the liquid ink as a shock or pressure wave. The shock waves originating at the wide end 112 of the exponential horn continue to move in a direction along the exponential born to the smaller end 106. As is evident from the shape of the horn as the wave passes from the end designated 112 to the end designated 106 the cross-sectional area of the horn is constantly decreasing. This in eltect results in the application of a given amount of shock wave over a smaller and smaller area thereby increasing the intensity of the wave.

It should be noted at this point that in order for a wave to be focused by the horn used, it is necessary that the acoustic impedances of the horn walls and its surrounding material are different, so that the wave does not diffuse to the horn surrounding material. It does not matter, for proper operation, whether the impedance of the surrounding material is greater or lesser than that of the horn, so long as they are different. The wave in this manner is built up to sufiicient intensity to be able to carry or force droplets of ink from the surface of the ink supply 122 along the remaining portion of the exponential horn 104 and be cast upon the lower surface 108 of the tape 110.

Referring now to FIGURE 2, there is shown an arrangement whereby a number of individual print elements may be organized into a matrix to permit the printing of a character composed of a plurality of individual spots producible by the individual elements. For example with that shown in FIGURE 2 it would be possible to generate a dash composed of three consecutive dots. The individual transducers 114 of the respective printing elements are connected to a set of terminals 1, 2 and 3 which in turn may be connected to a set of switches 51, 52 and 53 respectively, or an electrical selection matrix (not shown). Matrices or encoders of the type required are well known in the art as shown by the matrix of FIGURE 4-315 of the book High-Speed Computing Devices by the staff of Engineering Research Associates, Inc., published by McGraw-Hill Book Company, Inc., (1950) at page 43. By concurrently actuating the terminals 1, 2 and 3 it would be possible to force in the manner described above, three individual dots from the three respective printing elements shown to the surface 108 of the tape 110. Although the arrangement shown in FIGURE 2 has been illustrated, for simplicity purposes only, in a one dimensional arrangement, it should be understood that this method of arrangement of the respective printing elements may be extended to cover a two dimensional arrangement thereby permitting the selection and printing of characters along the width as well as length of the tape.

Referring now to FIGURE 3 there is shown another arrangement of the matrix shown in FIGURE 2. In this arrangement the respective exponential horns 104 are of different sizes. The central horn 104 is longer in its distance between the points 106 and 1 12 than the respective horns 104 to its right and left. This arrangement is used to permit a greater density of printing elements to be placed in a given area, thereby allowing for a greater density of printing of the individual dots. The greater density of printing elements is achieved by the more economical use of the space available. With the horns used (as shown in FIGURE 2) and placed along the same base line, the distance between a first and a third horn would be equal to two horn widths. However, by making the second horn longer than the first and third and placing it on a base line below that of the first and third horns, the separation is reduced. Now the separation between the first and third horns, is one horn width plus the width of the longer horn at the point it crosses the base line of horns one and three. The manner of operation of the respective devices are the same regardless of the length of the respective horn employed. The strength of the transducer or the value of voltage applied to it is adjusted to produce a uniform depositing of ink regardless of the length of the printing element employed to deposit the individual spot.

' Referring now to FIGURE 4 there is shown a portion of the tape 108 which has been printed by devices arranged in accordance with the invention, the matrix being arranged either as in FIGURE 2 or FIGURE 3.

While a relatively small matrix of printing elements has been shown in the respective FIGURES 1, 2 and 3 larger matrixes may be constructed or a plurality of these matrixes may be employed without departing from the inventive concepts disclosed herein. It will be understood that various omissions and substitutions and changes of the form and detail of the device illustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention.

What is claimed is: V

1. Printing means of the type wherein no direct force is exerted between a character forming means and the surface to be printed upon comprising:

(a) a plurality of shock wave conducting horn means arranged in a character forming matrix of rows and columns, each horn means having a small first and a larger second open end, alternate of said horn means in each row and column of said matrix being of greater length than the other of said horn means;

(b) means mounting said horn means whereby a closer arrangement of the first openings may be at tained with the smaller first open ends of all said horn means being arranged adjacent and parallel with the said surface to be printed upon and the larger second open ends of the horn means of greater length extending beyond the larger second open ends of said other horn means;

(c) an ink supply mounted so as to completely immerse each of said second open ends in said ink pp y;

(d) a plurality of shock wave producing transducer means, each placed within said ink supply and closely aligned with the larger second open end of individual ones of said horn means;

- (e) and means adapted to receive signals and in response thereto momentarily to excite selected ones of said shock wave producing means to produce shock waves in said ink, said waves traveling between said second and said first open ends of their associated horn means and forcing a portion of said ink out of said first open end to impinge upon said surface, each impingement of said ink upon said surface forming an ink spot thereon, said ink spots cooperating in the forming of a character on said surface in accordance with the pattern of the selected shock Wave producing means. 2. A construction according to claim 1 wherein said horn means are of the exponential type, and the shock Wave producing means are piezoelectric transducers.

References Cited by the Examiner UNITED STATES PATENTS 11/19 Zemke 1011 14 6/50 Hansell 239102 12/52 Daniell 310-26 X 10/57 6 2,874,634 2/59 Hense 101-93 2,975,703 3/61 Burkhardt.

FOREIGN PATENTS 218,925 12/58 Australia. 81,920 9/56 Denmark. 121,802 12/58 Russia.

OTHER REFERENCES Olson, H. F.: Acoustical Engineering, Princeton, NJ,

ROBERT E. PULFREY, Primary Examiner.

DeVol 101 1 15 R. A. LEIGHEY, EUGENE R. CAPOZIO, Examiners. 

1. PRINTING MEANS FO THE TYPE WHEREIN NO DIRECT FORCE IS EXERTED BETWEEN A CHARACTER FORMING MEANS AND THE SURFACE TO BE PRINTED UPON COMPRISING: (A) A PLURALITY OF SHOCK WAVE CONDUCTING HORN MEANS ARRANGED IN A CHARACTER FORMING MATRIX OF ROWS AND COLUMNS, EACH HORN MEANS HAVING A SMALL FIRST AND A LARGER SECOND OPEN END, ALTERNATE OF SAID HORN MEANS IN EACH ROW AND COLUMN OF SAID MATRIX BEING OF GREATER LENGTH THAN THE OTHER OF SAID HORN MEANS; (B) MEANS MOUNTING SAID HORN MEANS WHEREBY A CLOSER ARRANGEMENT OF THE FIRST OPENINGS MAY BE ATTAINED WITH THE SMALLER FIRST OPEN ENDS OF ALL SAID HORN MEANS BEING ARRANGED ADJACENT AND PARALLEL WITH THE SAID SURFACE TO BE PRINTED UPON AND THE LARGER SECOND OPEN ENDS OF THE HORN MEANS OF GREATER LENGTH EXTENDING BEYOND THE LARGER SECOND OPEN ENDS OF SAID OTHER HORN MEANS; (C) AN INK SUPPLY MOUNTED SO AS TO COMPLETELY IMMERSE EACH OF SAID SECOND OPEN ENDS IN SAID INK SUPPLY; (D) A PLURALITY OF SHOCK WAVE PRODUCING TRANSDUCER MEANS, EACH PLACED WITHIN SAID INK SUPPLY AND CLOSELY ALIGNED WITH THE LARGER SECOND OPEN END OF INDIVIDUAL ONES OF SAID HORN MEANS; (E) AND MEANS ADAPTED TO RECEIVE SIGNALS AND IN RESPONSE THERETO MOMENTARILY TO EXCITE SELECTED ONES OF SAID SHOCK WAVE PRODUCING MEANS TO PRODUCE SHOCK WAVES IN SAID INK, SAID WAVES TRAVELING BETWEEN SAID SECOND AND SAID FIRST OPEN ENDS OF THEIR ASSOCIATED HORN MEANS AND FORCING A PORTION OF SAID INK OUT OF SAID FIRST OPEN END TO IMPINGE UPON SAID SURFACE, EACH IMPINGEMENT OF SAID INK UPON SAID SURFACE FORMING AN INK SPOT THEREON, SAID INK SPOTS COOPERATING IN THE FORMING OF A CHARCTER ON SAID SURFACE IN ACCORDANCE WITH THE PATTERN OF THE SELECTED SHOCK WAVE PRODUCING MEANS. 